Gray, P., & Helmer, O. (1974). California futures study: Analysis of impacts of transportation planning : summary report. State of California, Business and Transportation Agency, Dept. of Transportation, Division of Transportation Planning.
芝加哥风格引文Gray, Paul, 与 Olaf Helmer. California Futures Study: Analysis of Impacts of Transportation Planning : Summary Report. [Sacramento]: State of California, Business and Transportation Agency, Dept. of Transportation, Division of Transportation Planning, 1974.
MLA引文Gray, Paul, 与 Olaf Helmer. California Futures Study: Analysis of Impacts of Transportation Planning : Summary Report. State of California, Business and Transportation Agency, Dept. of Transportation, Division of Transportation Planning, 1974.